[RFI] Re: [TowerTalk] Comment on Radar Engineers Model 240

Alan Robinson robinsah at engr.orst.edu
Mon Aug 11 21:13:48 EDT 2003

Hi Tod, K0TO,

I have a Radar Engineers Model 240 which I use for locating noise sources on
power lines. I highly recommend it. I also have a Radar Engineers Model 250
Ultrasonic Locator. The combination can not only find the offending pole, but
usually I can pick out the noise making hardware while remaining on the ground.

I like to use my Tektronix Model TDS-210 Oscilloscope with the 240, larger
display and easier to see. I run the scope off of an Astron Model Pi-250W power
inverter. It has a remarkably accurate crystal controlled frequency. This allows
synchronization with the power line frequency.

Normally I use a two or three element beam on 144 MHz to locate the "suspect"
pole with the 240, then I use a 440 MHz 6 element yagi to verify the pole, and
finally I use the 250 to pick out the hardware item on the pole. The Model 240
really is an outstanding piece of equipment, as is the 250.

You can read a story I wrote about my locating experience in Marv Loftness' new
edition of his AC Power Interference Handbook, available from the ARRL. Marv's
book is a "must read" for information on how to locate power line noise sources.

I hope this helps you. If you have any questions, but email me.

Sincerely, and 73s,

Alan, W4LKE

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